Factors affecting compressed carbon dioxide energy storage system in deep aquifers

Compressed air energy storage (CAES) technology is a vital solution for managing fluctuations in renewable energy, but conventional systems face challenges like low energy density and geographical constraints. This study explores an innovative approach utilizing deep aquifer compressed carbon dioxide (CO₂) energy storage to overcome these limitations. To identify the factors affecting compressed CO₂ energy storage system in deep aquifers, numerical simulations using T2well/ECO2N investigate hydrodynamic and thermodynamic behaviors, focusing on the impact of aquifer properties (depth, thickness, porosity, and permeability) and operational parameters (wellbore penetration depth through the aquifer and energy storage scale) on system performance. The findings reveal notable pressure variations in both the wellbore and aquifer during system operation and the injected supercritical CO₂, input by geothermal energy from the surrounding formations, contributes to high energy storage efficiency across the entire system. The impact factor analysis suggests medium aquifer depth and permeability, a storage space with high porosity, increased aquifer thickness, greater wellbore penetration depth, and larger energy storage scales contribute to the safe and efficient operation of the system.